The present invention relates to vehicle access systems.
Access systems, such as motorized lifts, have been used to transport people and cargo between different elevations, such as between ground level and the elevated entryway of a door. These access systems include platforms, ramps, moving seats, movable steps, and the like, which may be attached to stationary structures, such as buildings and loading docks, or mobile structures such as vehicles. Access systems have been used to provide disabled and mobility-impaired individuals access to structures that traditionally were accessible only via steps or stairs, or that required an individual to step over or across an obstacle. For example, motorized lifts and ramps have been used to allow disabled and mobility-impaired individuals to enter and exit vehicles.
Currently, many automotive manufacturers offer minivans that include a power sliding door system to automatically open or close one or both of the vehicle's sliding doors. Components such as these which are installed by the manufacturer of the vehicle are commonly referred to as OEM (Original Equipment Manufacturer) components. While the specific configurations of OEM power sliding door systems vary depending on the manufacturer, many of the systems include at least a body control module, a door control module, a receiver, a door switch, and a data bus. In some systems, the body control module, door control module, receiver and door switch are all in communication with the vehicle's data bus, which enables the body control module, door control module, receiver and door switch to communicate with each other and to receive signals from a user indicating that the user wants to open or close the door (a “door operation signal”). Generally, the user may communicate a door operation signal to the power sliding door system by pulling on a door handle of the vehicle, operating buttons positioned within the vehicle, or by pushing a button on a keyless entry device or key fob. In many cases, if the door operation signal is produced by a remote device, such as the key fob, the receiver detects a signal sent from the key fob and communicates detection of that signal to the door control module which in turn operates the power sliding door system to open or close the door. If a user pulls on the door handle to initiate powered opening or closing of the door, a door switch in the door handle may close to send a door operation signal to one or both of the body control module or the door control module.
Before manufacturers provided OEM power sliding door systems, vehicle access system providers generally installed their own door control systems, including a door motor, door sensors, and the like. Such providers would also install a powered ramp or lift device including a ramp motor and a ramp control system. Now that manufacturers are providing OEM powered door control systems, the aftermarket access system providers must coordinate operation of their ramp control systems with the operation of the OEM door control systems. Some examples of how aftermarket ramp systems and OEM door systems are coordinated are disclosed in U.S. Pat. No. 6,825,628, the contents of which are hereby incorporated by reference. Existing access control systems include specialized controllers that are spliced into the OEM wiring systems of the vehicle, such as the data bus, to intercept or otherwise detect signals transmitted along the OEM wiring systems. These controllers are able to delay or suspend the transmission of certain of these signals such that, for example, closing of the power sliding door can be delayed or suspended until such time as an access ramp is fully stowed. Similarly, the systems are configured to detect commands sent to the door control module and/or the body control module for opening the power sliding door. Upon determining that the door is fully open, the systems begin deploying the ramp.